Coronary angiography is regarded as the "gold standard" for the assessment of coronary artery disease.However,coronary angiography is limited by its two-dimensional(2-D) representation of three-dimensional(3-D) structures.Based on 3-D reconstruction of coronary arterial tree,a method was proposed to calculate the 3-D values of diameter,length,and branch angle in 3-D quantitative coronary angiography(QCA).2-D QCA and 3-D QCA were compared in the accuracy of quantification using images of vessel phantom.The experiments show 3-D QCA can get more accurate results.Therefore,3-D QCA using the proposed method is capable of the reliable assessment of stenosis or selection and placement of stents during diagnostic and interventional procedures.